21.1.1 Migration of Common Java Classes with Aliases Applied

In Oracle Fusion Middleware 11g Release 1 (11.1.1), there is the concept of the "built-in" dictionary which is linked to by all other dictionaries. The built-in dictionary includes fact types for several common Java classes, including: Object, String, BigInteger, BigDecimal, Calendar, XMLGregorianCalendar, List, and JAXBElement.

There is a limitation when you are migrating a Release 10.1.3.x dictionary to Oracle Fusion Middleware 11g Release 1 (11.1.1). In Oracle Business Rules Release 10.1.3.x, all classes had to be imported into each dictionary, including Object which was imported by default. Thus, a user could import the common Java class fact types and change the aliases for properties, methods, and fields. In Oracle Fusion Middleware 11g Release 1 (11.1.1), for such classes users cannot specify custom aliases and these fact types are not migrated from a Release 10.1.3.x dictionary that is being migrated to Oracle Fusion Middleware 11g Release 1 (11.1.1). Thus, if an alias is applied for a common Java class that is part of the built-in dictionary, in Oracle Fusion Middleware 11g Release 1 (11.1.1) these aliases are discarded and the aliases are not available to use in rules.

During dictionary migration from Oracle Business Rules Release 10.1.3.x, Java classes are imported into the new Oracle Fusion Middleware 11g Release 1 (11.1.1) dictionary and then aliases and visibility settings are applied. A bug in the migration prevents the identification of some methods so that alias and visibility settings can be applied.

Workaround:

In such cases, the alias and visibility settings that applied for the Oracle Business Rules Release 10.1.3.x dictionary must be manually applied to the destination Oracle Fusion Middleware 11g Release 1 (11.1.1) dictionary.

Oracle Business Rules Release 10.1.3.x uses JAXB 1.0. In JAXB 1.0 restricted simple types do not have any special support in the generated Java classes, and are mapped to a property with the same type as the simple type. Oracle Business Rules for Oracle Fusion Middleware 11g Release 1 (11.1.1) uses JAXB 2.0. In JAXB 2.0, restricted simple types of string type are transformed into Java enum values. Because of this difference, after migrating a Release 10.1.3.x dictionary, places in the dictionary that previously used raw strings to represent the restricted values must be manually updated to use the Java enum values.

xsd:dateTime in Migrated Dictionaries

Oracle Business Rules Release 10.1.3.x uses JAXB 1.0. In JAXB 1.0, xsd:dateTime types are mapped to java.util.Calendar. Oracle Business Rules for Oracle Fusion Middleware 11g Release 1 (11.1.1) uses JAXB 2.0. In JAXB 2.0, xsd:dateTime types are mapped to XMLGregorianCalendar, which more accurately contains the values of an xsd:dateTime element. Thus, in a dictionary migrated from Release 10.1.3.x, comparisons between properties may no longer function correctly because Calendar implements a method compareTo and XMLGregorianCalendar implements a method compare. Manual changes are required in the dictionary to change the comparisons. Alternatively, in Oracle Fusion Middleware 11g Release 1 (11.1.1) you can use a Duration to compare most common date and time formats. Making this change in a migrated dictionary requires manual changes to the data model and to the rules that use the imported fact types.

Invalid Expressions in Migrated Dictionary

Oracle Business Rules for Oracle Fusion Middleware 11g Release 1 (11.1.1) supports rich type-checking that invalidates some expressions migrated from Release 10.1.3.x. For example, if an instance of Integer is referenced to call the intValue() method, this may produce a validation warning if Integer has not been imported into the data model. The solution to this issue is to import Integer into the data model.

Index-based or Iterator-based Iteration in Collections with RL Functions

In Release 10.1.3.x, it was necessary in functions and RL actions to use index-based or iterator-based iteration over collections with raw RL. In Oracle Fusion Middleware 11g Release 1 (11.1.1), the pre-defined action type "for" implements the for-each iteration loop construct and can replace most uses of these older iteration constructs.

Calling Functions to Return New Variable Instances

In Release 10.1.3.x, it was not possible to invoke a constructor in the initialization expression for a variable. In Oracle Fusion Middleware 11g Release 1 (11.1.1) variables are called globals. Due to this Release 10.1.3.x limitation, in some Release 10.1.3.x dictionaries, there are function calls to initialize expressions and to invoke the constructor and return the new instance. In Oracle Fusion Middleware 11g Release 1 (11.1.1), you can use the new operator in initialization expressions.

21.1.4 Migrator Does not Migrate Certain Java Fact Type Properties

In Release 10.1.3.x, a property was created for a fact type if the fact type had either a setter or getter. In Oracle Fusion Middleware 11g Release 1 (11.1.1), a property is created only if there is both a setter and a getter for the property.

21.1.5 Migrator Throws a RUL-05003 Warning in Some Cases

In Oracle Fusion Middleware 11g Release 1 (11.1.1), there is a requirement that Java and XML fact types in a dictionary have a single-inheritance chain as determined by visible fact types. This limitation prevents multiple-inheritance chains, including interfaces, from causing runtime exceptions in the engine. The user must specify a single-inheritance chain by marking classes which should not be considered in an inheritance chain as non-visible. When a multiple-inheritance chain is detected during validation, the follow warning is returned:

RUL-05003: The visible fact type "Foo" should only inherit from one visible fact type, but inherits from visible fact types "Bar" and "Baz".

In this case, marking either Bar or Baz as non-visible will fix this warning.

21.1.6 Hiding Certain Properties When Using Classes with Misbehaving Methods

When asserting instances of some classes exceptions may be thrown because of misbehaving methods. When a fact is asserted, the fact is "shadowed" inside the rules engine. This shadowing requires the rules engine to invoke the accessors for all properties with the Visible checkbox selected (for all visible properties). If an accessor throws an exception when it is invoked, this exception propagates out of the rules engine.

A specific example of this limitation is the java.sql.Date class. This class includes several deprecated methods, for example getYears and setYears. These methods always throw an IllegalArgumentException when they are invoked. In Oracle Business Rules, if an instance of the Date class is asserted, an exception is thrown. This exception is due to the getYears method being called when the fact instances are shadowed inside the rules engine.

When using Oracle Business Rules, the Date class should not be asserted, but this assert may be out of the control of the user. For example the Date class is asserted when a large object graph contains a list of Date instances and you are using assert tree on the object graph.

Workaround:

You must mark all properties that include misbehaving methods as non visible. To do this you must deselect the Visible checkbox for the properties that cause an exception. For example, in the java.sql.Date class., the workaround is to deselect the Visible checkbox for the properties "years", "hours", and "minutes" for the java.sql.Date fact type in the datamodel.

21.1.7 Length of Rules Repository Path Should be Less Than 70 Characters

While configuring the rules repository path, it is recommended to limit the length of the path to 70 characters. If the length exceeds 70 characters, you would encounter problems after any DT/RT changes from SOA Composer.

So, as a best practice, after you design the rules, ensure that the repository path length is less than 70 characters.The following path taken from a sample rule.decs file fails after DT/RT changes at run time:

For more information, see the descriptions in oracle.rules.rl.extensions.RL, in Oracle Fusion Middleware Java API Reference for Oracle Business Rules Javadoc.

Expressions can support a variable number of arguments. As in the Java Language, when the last parameter to a function or method is an array, then an expression can call the function or method with a variable number of arguments. For example, using the built-in RL.list.create function in an expression:

RL.list.create(Object[] items) returns List

The built-in RL.list.create() can be called as follows:

(assign new) List myList = RL.list.create(1, 2.0, "three")

In this example, the myList result contains three Objects: an Integer, a Double, and a String.

After you upgrade AS11 Oracle Business Rules components to AS11 PS2, the audit trail for the composite instances created before upgrade shows only basic information. The decision trace includes only the name of the Decision Function invoked and the timestamp.

Workaround:

You can view other details of the trace, such as the values of input and output facts by using the BPELProcess Audit Trail.

SOA Composer provides only a subset of the functionality available in Rules Designer. Some of the features/tabs in Rules Designer are currently not available in SOA Composer. For example, the Functions tab functionality is missing, the Links tab functionality is missing, and you cannot add new rulesets with SOA Composer.

Using SOA Composer with a Decision Table, the split and merge selected cells operations do not work.

There is no workaround for this issue.

21.1.12 SOA Composer Does Not Support Localized Number Formatting

SOA Composer does not support any number formatting. For example, you are using SOA Composer with U.S. English as the browser language. You enter a floating-point data, such as 34533223.2345, as a value. However, when you change the browser language to French, the value is still displayed as 34533223.2345. In French, the value should have been displayed as 34533223,2345.

Workaround:

Irrespective of the browser language, you need to enter any numeric value in the U.S. English language without any number separator such as ",".

21.1.13 In SOA Composer, Collapsed Rules Do Not Show or Highlight Errors

In SOA Composer, in the case of a rule in a collapsed state, when you double-click an error in the Validation Panel, the UI does not display a window with the error messages.However, in the case of a rule in an expanded state, when you double-click an error message in the Validation Panel, the UI opens a window with the error message, and also highlights erroneous areas.

21.2 Configuration Issues and Workarounds

21.2.1 Too Many Open Files Message When Deploying a Business Rules Project

If you see the error "Too Many Open Files" while deploying an Oracle Business Rules Decision Component, you might need to increase the file descriptor limit.

The "Too many open files" issue is due to JDK6 bugs. These bugs could occur at runtime or at compile time, depending on the number of JAR files used and a few other variations around the use of file descriptors by the JDK/JRE.

Workaround for this issue is to increase the limit of file descriptors. Per-process, per-user file descriptor limit can be preconfigured by default to the value 1024. If you increase this limit to 4096 or larger, the new value should resolve this issue.

The command to increase per-process, per-user file descriptor differs across Operating Systems and shells. It is typically done with ulimit on UNIX platforms so consult the man pages for ulimit for your Operating System and shell.

For example:

$ ulimit -n 4096

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